Vertical Imbalance Calculator
This tool is intended for educational and dispensing support use.
It calculates vertical imbalance at reading level using binocular prescription and add power.
Summary Output
Enter binocular prescription, add power, and reading level above, then submit the form.
How It Works
This version follows the old Java logic closely: it evaluates the 90th meridian power of each eye after including the add power, then applies Prentice’s Rule at the reading level.
The stronger eye in the 90th meridian determines the direction reported in the result.